A series of orange-emitting Rb 2CaP 2O 7:Eu 2+ phosphors were synthesized by a conventional solid-state reaction method. The as-prepared phosphors were characterized by X-ray powder diffraction (XRD), fluorescence spectroscopy, and spectroradiometry. XRD showed that all prepared samples exhibited a monoclinic Rb 2CaP 2O 7 phase. Fluorescence spectroscopy showed that the photoluminescence efficiency of Rb 2Ca 1-xP 2O 7:Eu x 2+ phosphors increased with increasing Eu 2+ concentration until x = 0.006, then decreased at higher concentrations, due to a concentration quenching effect. The thermal activation energy was also measured to be 0.40 eV. Furthermore, a phosphor-converted LED (pc-LED) coated with Rb 2Ca 0.994P 2O 7:Eu 0.006 2+ was fabricated, which exhibited bright orange emission under a forward bias, from 200 to 300 mA. The color rendering index (CRI) of pc-LED coated with Rb 2Ca 0.994P 2O 7:Eu 0.006 2+ was higher than the CRI of pc-LED coated with commercial red phosphor, due to the broad emission band of Rb 2CaP 2O 7:Eu 2+ phosphor. In applying with three-band pc-LEDs, moreover, white pc-LED using Rb 2CaP 2O 7:Eu 2+ phosphor had a higher CRI, than using commercial phosphor. These results indicated that Rb 2CaP 2O 7:Eu 2+ phosphor could be a good candidate for a near-UV based w-LED.
|Number of pages||5|
|Journal||Materials Research Bulletin|
|Publication status||Published - 2012 Dec|
Bibliographical noteFunding Information:
This work was supported by the IT R&D program of MKE/IITA [2009-F-020-01, Development of red nitride phosphor and self-assembly phosphorescent layer packaging technology for high rendition LED illumination] and Samsung LED Co., Ltd and by the National Research Foundation of Korea Grant funded by the Korean Government (MEST) ( NRF-2011-0030745 ). Characterization of the materials was supported by Research Institute of Advanced Materials (RIAM).
Copyright 2012 Elsevier B.V., All rights reserved.
- A. Inorganic compounds
- A. Optical materials
- D. Luminescence
- D. Optical properties
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering